Everyone who have had and have farm animals or pets know that to prevent animals from entering areas they should not be can be challenging. This usually requires fencing, which is more or less demanding. Good animal welfare is desirable for all animal owners. Lack of animal welfare is often caused by reduced freedom. This is often caused by difficulties in building fences that are good enough and that provide adequate space.
Pastures grow, and the cultural landscape, most places is in the process of disappearing. This is a trend which grows worse every year. The reason for this is not one-sided. Both that the growing season gets longer each year and the number of grazing animals is reduced contribute to the fact that we do not have the ability to maintain an open landscape. The greatest reason for this is that the number of grazing animals in uncultivated land is reduced due to fencing is costly and time consuming. Many therefore see that the profitability in conducting grazing animals is not large enough in relation to workload. This results in that overgrown is and becomes an increasing problem. It is necessary to think new. In addition to this the pasture represents a resource that to a low degree is utilized. Grazing animals can utilize this resource in the best manner.
For some grazing animals, such as cattle, it is common to gradually expand the grazing area. This is to increase the utilization of the pasture. Today's systems do not provide a sufficient opportunity to implement this because it is both time consuming and an extensive operation. In most cases this is not done in a sufficient extent. There is therefore a need for an invention which can realize automatic strip grazing. In this way, the pasture could be utilized in the best possible way.
Milk cows live usually their entire life inside. The reason for this is the amount of work required to release milk cows for grazing. The workload is great because it today is necessary with manual collection of animals before milking is performed. Both if manual milking is done, but also if a milk robot is used. It is therefore a need for an invention that allows automatic collection of animals. This could increase the possibilities of releasing milk cows to pastures with no extra effort.
Invisible fencing (“Virtual fencing”) of animals is described in, amongst others, in the publications US2008272920A, U.S. Pat. No. 6,581,546B, US2002196151A, WO0057692A, US2002017995A, U.S. Pat. No. 5,868,100A, US20080035072, U.S. Pat. Nos. 6,956,483 and 5,791,294.
None of these describe in detail how stimuli or correction should be performed, except that audio and/or electric shock is used. This with the exception of WO0057692A. In WO0057692A is however used triangulation of RF signal strength in the definition of an area. It is defined that warning is given in the form of that the sound level increases in four steps. It is then given sound signals in pulses. When the distance to a fence is over a certain distance, electric shock is given in certain intervals. The disadvantage with these four steps of alert must lie within a limited extent to avoid that each of these steps in stimuli not continues if the animal turns and moves back in the correct direction. It does not take into account possible panic. But the biggest insufficiency is the handling of animals that do not respond as intended. If the animal does not understand that it must return to avoid stimuli, the animal may experience continuous electric shocking. This could result in suffering for the animal.
One publication, U.S. Pat. No. 6,581,546B, describes dynamic change of area, but it is not used in connection with the change of grazing land. It is used as a method to prevent the animal from moving past the area of stimuli.
The most important issue regarding fencing of animals without the use of a physical fence, is that the animal must be given an intuitively understandable warning signal before an unpleasant stimuli is applied to the animal, comparable to the visual warning a physical fence provides. This warning signal must give the animal a good opportunity to avoid future discomfort, and at the same time instruct the animal to move in the right direction (reverse). How this should be done is not well defined in the aforementioned publications. Disadvantages of prior art is thus that the described solutions may result in confused animals. They are neither adapted for both automatic collection of animals towards a defined area and migration of animals to new areas. The mentioned publications take in addition not in consideration that technical problems may arise. Also how these problems should be handled to avoid unnecessary distress or escape.
Testing of systems like this has proven a need for a system that automatically can adapt the discomfort (the electric shocks) strength to the animal that carries the system. This is because some individuals do not react as desired on the applied discomfort and may choose to cross the invisible border if desired when the drift is sufficiently strong.
Some animal species have a particularly prominent herd instinct. It is important that a system of invisible fencing takes account for this. None of the above publications mention this as something that must be taken into account. It is also a risk that a system for invisible fencing may unintentionally separate animals in a herd, which is important to take into account. This is important so good animal welfare is achieved.